System and method for processing messages being composed by a user

ABSTRACT

A system and method for processing messages being composed by a user of a computing device (e.g. a mobile device). Embodiments are described in which the performance of certain tasks is initiated before a direction is received from a user to send a message being composed by the user. This may involve, for example, “pre-fetching” security-related data that will be required in order to send a message that is in the process of being composed by the user securely. Such data may include security policy data, certificate data, and/or certificate status data, for example.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser.No.12/834,326, filed Jul. 12, 2010, which is a continuation of U.S. patentapplication Ser. No. 11/192,116, filed Jul. 29, 2005. U.S. patentapplication Ser. No. 12/834,326 issued to patent as U.S. Pat. No.8,037,149 and U.S. patent application Ser. No. 11/192,116 issued topatent as U.S. Pat. No. 7,756,932. The entire contents of applicationSer. Nos. 12/834,326, 11/192,116, are hereby incorporated by reference.

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

FIELD OF THE INVENTION

Embodiments of the invention relate generally to the processing ofmessages (e.g. electronic mail messages), and more specifically tosystems and methods for processing messages being composed by users ofcomputing devices (e.g. mobile devices).

BACKGROUND OF THE INVENTION

Electronic mail (“e-mail”) messages may be generally encoded using oneof a number of known protocols to facilitate secure messagecommunication. The Secure Multiple Internet Mail Extensions (“S/MIME”)protocol, for example, relies on public and private encryption keys toprovide confidentiality and integrity, and on a Public KeyInfrastructure (PKI) to communicate information that providesauthentication and authorization. Data encoded using a private key of aprivate key/public key pair can only be decoded using the correspondingpublic key of the pair, and data encoded using a public key of a privatekey/public key pair can only be decoded using the corresponding privatekey of the pair. In S/MIME, the authenticity of public keys used in theencoding of messages may be validated using certificates. Other knownstandards and protocols may be employed to facilitate secure messagecommunication, such as Pretty Good Privacy™ (PGP) and variants of PGPsuch as OpenPGP, for example. It is understood that as compared toS/MIME-based systems, PGP-based systems also utilize public and privateencryption keys to provide confidentiality and integrity, although theauthenticity of public keys used in the encoding of PGP messages arevalidated in a different manner. Constructs for providing a public keyand information on the key holder similar to that of a “certificate” (asused in S/MIME for example) may be provided in such other secure messagecommunication standards and protocols. One such construct is commonlyknown as a “PGP key” in PGP-based systems. For the purposes of thisspecification and the claims, the term “certificate” may be deemed toinclude such constructs.

Generally, before a new e-mail message that has been composed by a userof a computing device can be sent, it may be necessary to retrievecertain data to process the message, including for example: (1) securitypolicy data, which may identify a required security encoding for themessage; (2) certificate data, which typically includes a certificateholder's public key and other identification information associated withthe certificate holder; and/or (3) certificate status data, which may beused in verifying the status of a certificate (e.g. whether thecertificate has been revoked). While an e-mail message is beingcomposed, it is typically in a dynamic state until it is sent.Accordingly, only after the user has finished composing the e-mailmessage and directed the computing device to send the message (e.g. byselecting a “send” option provided by a messaging application) would thedata typically be retrieved and used to further process the messagebefore it is sent. This avoids unnecessary requests for the data, whichmight be made if the user who is composing a message ultimately decidesnot to send the message, for example.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of embodiments of the systems and methodsdescribed herein, and to show more clearly how they may be carried intoeffect, reference will be made, by way of example, to the accompanyingdrawings in which:

FIG. 1 is a block diagram of a mobile device in one exampleimplementation;

FIG. 2 is a block diagram of a communication subsystem component of themobile device of FIG. 1;

FIG. 3 is a block diagram of a node of a wireless network;

FIG. 4 is a block diagram illustrating components of a host system inone example configuration;

FIG. 5A is a flowchart illustrating steps in a method of processingmessages being composed by a user of a mobile device in one exampleembodiment; and

FIG. 5B is a flowchart illustrating steps in a method of processingmessages being composed by a user of a mobile device in another exampleembodiment.

DETAILED DESCRIPTION

As described in the above example, only after the user has finishedcomposing an e-mail message and directed a computing device to send themessage to activate the send process, would data such as security policydata, certificate data, and/or certificate status data generally beretrieved to further process the message. On a typical wired network,the time to complete the necessary requests to retrieve such data istypically minimal, and therefore, the process of obtaining this data inorder to facilitate the sending of the message is often transparent tothe user. On many wireless networks, however, the time to obtain therequired data could be much longer, which may result in a significantdelay in the send process as perceived by the user.

In contrast to prior art systems that defer the initiation of theretrieval of such data until after a direction is received from the userto send the message, in order to avoid unnecessary requests for thedata, it may nonetheless be desirable to employ a technique in whichdelays in the send process that might be experienced by users of certaincomputing devices such as mobile devices may be minimized such that thesend process will appear more transparent to such users.

Embodiments described herein relate generally to systems and methods inwhich the performance of certain tasks is initiated while a user iscomposing a message and before a direction is received from the user tosend the message. This may involve “pre-fetching” data that will likelybe required in order to send a message that is in the process of beingcomposed by the user, for example. Initiating the performance of suchtasks in advance will generally increase the likelihood that a messagewill appear to be sent quickly from the user's perspective, as the tasksrequired to complete the send process might already have been completed,or at the very least, will have already been initiated by the time thedirection to send the message is received from the user. This canenhance the usability of a computing device, and may be particularlyadvantageous when the computing device is a mobile device.

In one broad aspect, there is provided a method of processing messagesbeing composed by a user of a computing device, the method comprisingthe steps of: receiving a request from a user to compose a message;detecting when at least one triggering event associated with the messagebeing composed by the user has occurred; and for each triggering event,initiating performance of at least one task associated with therespective triggering event while the message is being composed by theuser, after detecting the occurrence of the respective triggering event.

In another broad aspect, there is provided a method of processingmessages being composed by a user of a computing device, wherein thetask associated with at least one triggering event includes retrievingdata that would be required to further process the message beingcomposed by the user should the user direct the message to be sent.

In at least one embodiment, the computing device is a mobile device.

These and other aspects and features of various embodiments will bedescribed in greater detail below.

Some embodiments of the systems and methods described herein makereference to a mobile device. A mobile device is a two-way communicationdevice with advanced data communication capabilities having thecapability to communicate with other computer systems. A mobile devicemay also include the capability for voice communications. Depending onthe functionality provided by a mobile device, it may be referred to asa data messaging device, a two-way pager, a cellular telephone with datamessaging capabilities, a wireless Internet appliance, or a datacommunication device (with or without telephony capabilities). A mobiledevice communicates with other devices through a network of transceiverstations.

To aid the reader in understanding the structure of a mobile device andhow it communicates with other devices, reference is made to FIGS. 1through 3.

Referring first to FIG. 1, a block diagram of a mobile device in oneexample implementation is shown generally as 100. Mobile device 100comprises a number of components, the controlling component beingmicroprocessor 102. Microprocessor 102 controls the overall operation ofmobile device 100. Communication functions, including data and voicecommunications, are performed through communication subsystem 104.Communication subsystem 104 receives messages from and sends messages toa wireless network 200. In this example implementation of mobile device100, communication subsystem 104 is configured in accordance with theGlobal System for Mobile Communication (GSM) and General Packet RadioServices (GPRS) standards. The GSM/GPRS wireless network is usedworldwide and it is expected that these standards will be supersededeventually by Enhanced Data GSM Environment (EDGE) and Universal MobileTelecommunications Service (UMTS). New standards are still beingdefined, but it is believed that they will have similarities to thenetwork behaviour described herein, and it will also be understood bypersons skilled in the art that the invention is intended to use anyother suitable standards that are developed in the future. The wirelesslink connecting communication subsystem 104 with network 200 representsone or more different Radio Frequency (RF) channels, operating accordingto defined protocols specified for GSM/GPRS communications. With newernetwork protocols, these channels are capable of supporting both circuitswitched voice communications and packet switched data communications.

Although the wireless network associated with mobile device 100 is aGSM/GPRS wireless network in one example implementation of mobile device100, other wireless networks may also be associated with mobile device100 in variant implementations. Different types of wireless networksthat may be employed include, for example, data-centric wirelessnetworks, voice-centric wireless networks, and dual-mode networks thatcan support both voice and data communications over the same physicalbase stations. Combined dual-mode networks include, but are not limitedto, Code Division Multiple Access (CDMA) or CDMA2000 networks, GSM/GPRSnetworks (as mentioned above), and future third-generation (3G) networkslike EDGE and UMTS. Some older examples of data-centric networks includethe Mobitex™ Radio Network and the DataTAC™ Radio Network. Examples ofolder voice-centric data networks include Personal Communication Systems(PCS) networks like GSM and Time Division Multiple Access (TDMA)systems.

Microprocessor 102 also interacts with additional subsystems such as aRandom Access Memory (RAM) 106, flash memory 108, display 110, auxiliaryinput/output (I/O) subsystem 112, serial port 114, keyboard 116, speaker118, microphone 120, short-range communications 122 and other devices124.

Some of the subsystems of mobile device 100 performcommunication-related functions, whereas other subsystems may provide“resident” or on-device functions. By way of example, display 110 andkeyboard 116 may be used for both communication-related functions, suchas entering a text message for transmission over network 200, anddevice-resident functions such as a calculator or task list. Operatingsystem software used by microprocessor 102 is typically stored in apersistent store such as flash memory 108, which may alternatively be aread-only memory (ROM) or similar storage element (not shown). Thoseskilled in the art will appreciate that the operating system, specificdevice applications, or parts thereof, may be temporarily loaded into avolatile store such as RAM 106.

Mobile device 100 may send and receive communication signals overnetwork 200 after required network registration or activation procedureshave been completed. Network access is associated with a subscriber oruser of a mobile device 100. To identify a subscriber, mobile device 100requires a Subscriber Identity Module or “SIM” card 126 to be insertedin a SIM interface 128 in order to communicate with a network. SIM 126is one type of a conventional “smart card” used to identify a subscriberof mobile device 100 and to personalize the mobile device 100, amongother things. Without SIM 126, mobile device 100 is not fullyoperational for communication with network 200. By inserting SIM 126into SIM interface 128, a subscriber can access all subscribed services.Services could include: web browsing and messaging such as e-mail, voicemail, Short Message Service (SMS), and Multimedia Messaging Services(MMS). More advanced services may include: point of sale, field serviceand sales force automation. SIM 126 includes a processor and memory forstoring information. Once SIM 126 is inserted in SIM interface 128, itis coupled to microprocessor 102. In order to identify the subscriber,SIM 126 contains some user parameters such as an International MobileSubscriber Identity (IMSI). An advantage of using SIM 126 is that asubscriber is not necessarily bound by any single physical mobiledevice. SIM 126 may store additional subscriber information for a mobiledevice as well, including datebook (or calendar) information and recentcall information.

Mobile device 100 is a battery-powered device and includes a batteryinterface 132 for receiving one or more rechargeable batteries 130.Battery interface 132 is coupled to a regulator (not shown), whichassists battery 130 in providing power V+ to mobile device 100. Althoughcurrent technology makes use of a battery, future technologies such asmicro fuel cells may provide the power to mobile device 100.

Microprocessor 102, in addition to its operating system functions,enables execution of software applications on mobile device 100. A setof applications that control basic device operations, including data andvoice communication applications, will normally be installed on mobiledevice 100 during its manufacture. Another application that may beloaded onto mobile device 100 would be a personal information manager(PIM). A PIM has functionality to organize and manage data items ofinterest to a subscriber, such as, but not limited to, e-mail, calendarevents, voice mails, appointments, and task items. A PIM application hasthe ability to send and receive data items via wireless network 200. PIMdata items may be seamlessly integrated, synchronized, and updated viawireless network 200 with the mobile device subscriber's correspondingdata items stored and/or associated with a host computer system. Thisfunctionality creates a mirrored host computer on mobile device 100 withrespect to such items. This can be particularly advantageous where thehost computer system is the mobile device subscriber's office computersystem.

Additional applications may also be loaded onto mobile device 100through network 200, auxiliary I/O subsystem 112, serial port 114,short-range communications subsystem 122, or any other suitablesubsystem 124. This flexibility in application installation increasesthe functionality of mobile device 100 and may provide enhancedon-device functions, communication-related functions, or both. Forexample, secure communication applications may enable electroniccommerce functions and other such financial transactions to be performedusing mobile device 100.

Serial port 114 enables a subscriber to set preferences through anexternal device or software application and extends the capabilities ofmobile device 100 by providing for information or software downloads tomobile device 100 other than through a wireless communication network.The alternate download path may, for example, be used to load anencryption key onto mobile device 100 through a direct and thus reliableand trusted connection to provide secure device communication.

Short-range communications subsystem 122 provides for communicationbetween mobile device 100 and different systems or devices, without theuse of network 200. For example, subsystem 122 may include an infrareddevice and associated circuits and components for short-rangecommunication. Examples of short range communication would includestandards developed by the Infrared Data Association (IrDA), Bluetooth,and the 802.11 family of standards developed by IEEE.

In use, a received signal such as a text message, an e-mail message, orweb page download will be processed by communication subsystem 104 andinput to microprocessor 102. Microprocessor 102 will then process thereceived signal for output to display 110 or alternatively to auxiliaryI/O subsystem 112. A subscriber may also compose data items, such ase-mail messages, for example, using keyboard 116 in conjunction withdisplay 110 and possibly auxiliary I/O subsystem 112. Auxiliarysubsystem 112 may include devices such as: a touch screen, mouse, trackball, infrared fingerprint detector, or a roller wheel with dynamicbutton pressing capability. Keyboard 116 is an alphanumeric keyboardand/or telephone-type keypad. A composed item may be transmitted overnetwork 200 through communication subsystem 104.

For voice communications, the overall operation of mobile device 100 issubstantially similar, except that the received signals would be outputto speaker 118, and signals for transmission would be generated bymicrophone 120. Alternative voice or audio I/O subsystems, such as avoice message recording subsystem, may also be implemented on mobiledevice 100. Although voice or audio signal output is accomplishedprimarily through speaker 118, display 110 may also be used to provideadditional information such as the identity of a calling party, durationof a voice call, or other voice call related information.

Referring now to FIG. 2, a block diagram of the communication subsystemcomponent 104 of FIG. 1 is shown. Communication subsystem 104 comprisesa receiver 150, a transmitter 152, one or more embedded or internalantenna elements 154, 156, Local Oscillators (LOs) 158, and a processingmodule such as a Digital Signal Processor (DSP) 160.

The particular design of communication subsystem 104 is dependent uponthe network 200 in which mobile device 100 is intended to operate, thusit should be understood that the design illustrated in FIG. 2 servesonly as one example. Signals received by antenna 154 through network 200are input to receiver 150, which may perform such common receiverfunctions as signal amplification, frequency down conversion, filtering,channel selection, and analog-to-digital (A/D) conversion. ND conversionof a received signal allows more complex communication functions such asdemodulation and decoding to be performed in DSP 160. In a similarmanner, signals to be transmitted are processed, including modulationand encoding, by DSP 160. These DSP-processed signals are input totransmitter 152 for digital-to-analog (D/A) conversion, frequency upconversion, filtering, amplification and transmission over network 200via antenna 156. DSP 160 not only processes communication signals, butalso provides for receiver and transmitter control. For example, thegains applied to communication signals in receiver 150 and transmitter152 may be adaptively controlled through automatic gain controlalgorithms implemented in DSP 160.

The wireless link between mobile device 100 and a network 200 maycontain one or more different channels, typically different RF channels,and associated protocols used between mobile device 100 and network 200.A RF channel is a limited resource that must be conserved, typically dueto limits in overall bandwidth and limited battery power of mobiledevice 100.

When mobile device 100 is fully operational, transmitter 152 istypically keyed or turned on only when it is sending to network 200 andis otherwise turned off to conserve resources. Similarly, receiver 150is periodically turned off to conserve power until it is needed toreceive signals or information (if at all) during designated timeperiods.

Referring now to FIG. 3, a block diagram of a node of a wireless networkis shown as 202. In practice, network 200 comprises one or more nodes202. Mobile device 100 communicates with a node 202 within wirelessnetwork 200. In the example implementation of FIG. 3, node 202 isconfigured in accordance with General Packet Radio Service (GPRS) andGlobal Systems for Mobile (GSM) technologies. Node 202 includes a basestation controller (BSC) 204 with an associated tower station 206, aPacket Control Unit (PCU) 208 added for GPRS support in GSM, a MobileSwitching Center (MSC) 210, a Home Location Register (HLR) 212, aVisitor Location Registry (VLR) 214, a Serving GPRS Support Node (SGSN)216, a Gateway GPRS Support Node (GGSN) 218, and a Dynamic HostConfiguration Protocol (DHCP) 220. This list of components is not meantto be an exhaustive list of the components of every node 202 within aGSM/GPRS network, but rather a list of components that are commonly usedin communications through network 200.

In a GSM network, MSC 210 is coupled to BSC 204 and to a landlinenetwork, such as a Public Switched Telephone Network (PSTN) 222 tosatisfy circuit switched requirements. The connection through PCU 208,SGSN 216 and GGSN 218 to the public or private network (Internet) 224(also referred to herein generally as a shared network infrastructure)represents the data path for GPRS capable mobile devices. In a GSMnetwork extended with GPRS capabilities, BSC 204 also contains a PacketControl Unit (PCU) 208 that connects to SGSN 216 to controlsegmentation, radio channel allocation and to satisfy packet switchedrequirements. To track mobile device location and availability for bothcircuit switched and packet switched management, HLR 212 is sharedbetween MSC 210 and SGSN 216. Access to VLR 214 is controlled by MSC210.

Station 206 is a fixed transceiver station. Station 206 and BSC 204together form the fixed transceiver equipment. The fixed transceiverequipment provides wireless network coverage for a particular coveragearea commonly referred to as a “cell”. The fixed transceiver equipmenttransmits communication signals to and receives communication signalsfrom mobile devices within its cell via station 206. The fixedtransceiver equipment normally performs such functions as modulation andpossibly encoding and/or encryption of signals to be transmitted to themobile device in accordance with particular, usually predetermined,communication protocols and parameters, under control of its controller.The fixed transceiver equipment similarly demodulates and possiblydecodes and decrypts, if necessary, any communication signals receivedfrom mobile device 100 within its cell. Communication protocols andparameters may vary between different nodes. For example, one node mayemploy a different modulation scheme and operate at differentfrequencies than other nodes.

For all mobile devices 100 registered with a specific network, permanentconfiguration data such as a user profile is stored in HLR 212. HLR 212also contains location information for each registered mobile device andcan be queried to determine the current location of a mobile device. MSC210 is responsible for a group of location areas and stores the data ofthe mobile devices currently in its area of responsibility in VLR 214.Further VLR 214 also contains information on mobile devices that arevisiting other networks. The information in VLR 214 includes part of thepermanent mobile device data transmitted from HLR 212 to VLR 214 forfaster access. By moving additional information from a remote HLR 212node to VLR 214, the amount of traffic between these nodes can bereduced so that voice and data services can be provided with fasterresponse times and at the same time requiring less use of computingresources.

SGSN 216 and GGSN 218 are elements added for GPRS support; namely packetswitched data support, within GSM. SGSN 216 and MSC 210 have similarresponsibilities within wireless network 200 by keeping track of thelocation of each mobile device 100. SGSN 216 also performs securityfunctions and access control for data traffic on network 200. GGSN 218provides internetworking connections with external packet switchednetworks and connects to one or more SGSN's 216 via an Internet Protocol(IP) backbone network operated within the network 200. During normaloperations, a given mobile device 100 must perform a “GPRS Attach” toacquire an IP address and to access data services. This requirement isnot present in circuit switched voice channels as Integrated ServicesDigital Network (ISDN) addresses are used for routing incoming andoutgoing calls. Currently, all GPRS capable networks use private,dynamically assigned IP addresses, thus requiring a DHCP server 220connected to the GGSN 218. There are many mechanisms for dynamic IPassignment, including using a combination of a Remote AuthenticationDial-In User Service (RADIUS) server and DHCP server. Once the GPRSAttach is complete, a logical connection is established from a mobiledevice 100, through PCU 208, and SGSN 216 to an Access Point Node (APN)within GGSN 218. The APN represents a logical end of an IP tunnel thatcan either access direct Internet compatible services or private networkconnections. The APN also represents a security mechanism for network200, insofar as each mobile device 100 must be assigned to one or moreAPNs and mobile devices 100 cannot exchange data without firstperforming a GPRS Attach to an APN that it has been authorized to use.The APN may be considered to be similar to an Internet domain name suchas “myconnection.wireless.com”.

Once the GPRS Attach is complete, a tunnel is created and all traffic isexchanged within standard IP packets using any protocol that can besupported in IP packets. This includes tunneling methods such as IP overIP as in the case with some IPSecurity (IPsec) connections used withVirtual Private Networks (VPN). These tunnels are also referred to asPacket Data Protocol (PDP) Contexts and there are a limited number ofthese available in the network 200. To maximize use of the PDP Contexts,network 200 will run an idle timer for each PDP Context to determine ifthere is a lack of activity. When a mobile device 100 is not using itsPDP Context, the PDP Context can be deallocated and the IP addressreturned to the IP address pool managed by DHCP server 220.

Referring now to FIG. 4, a block diagram illustrating components of ahost system in one example configuration is shown. Host system 250 willtypically be a corporate office or other local area network (LAN), butmay instead be a home office computer or some other private system, forexample, in variant implementations. In this example shown in FIG. 4,host system 250 is depicted as a LAN of an organization to which a userof mobile device 100 belongs.

LAN 250 comprises a number of network components connected to each otherby LAN connections 260. For instance, a user's desktop computing device(“desktop computer”) 262 a with an accompanying cradle 264 for theuser's mobile device 100 is situated on LAN 250. Cradle 264 for mobiledevice 100 may be coupled to computer 262 a by a serial or a UniversalSerial Bus (USB) connection, for example. Other user computers 262 b arealso situated on LAN 250, and each may or may not be equipped with anaccompanying cradle 264 for a mobile device. Cradle 264 facilitates theloading of information (e.g. PIM data, private symmetric encryption keysto facilitate secure communications between mobile device 100 and LAN250) from user computer 262 a to mobile device 100, and may beparticularly useful for bulk information updates often performed ininitializing mobile device 100 for use. The information downloaded tomobile device 100 may include S/MIME certificates or PGP keys used inthe exchange of messages. The process of downloading information from auser's desktop computer 262 a to the user's mobile device 100 may alsobe referred to as synchronization.

It will be understood by persons skilled in the art that user computers262 a, 262 b will typically be also connected to other peripheraldevices not explicitly shown in FIG. 4. Furthermore, only a subset ofnetwork components of LAN 250 are shown in FIG. 4 for ease ofexposition, and it will be understood by persons skilled in the art thatLAN 250 will comprise additional components not explicitly shown in FIG.4, for this example configuration. More generally, LAN 250 may representa smaller part of a larger network [not shown] of the organization, andmay comprise different components and/or be arranged in differenttopologies than that shown in the example of FIG. 4.

In this example, mobile device 100 communicates with LAN 250 through anode 202 of wireless network 200 and a shared network infrastructure 224such as a service provider network or the public Internet. Access to LAN250 may be provided through one or more routers [not shown], andcomputing devices of LAN 250 may operate from behind a firewall or proxyserver 266.

In a variant implementation, LAN 250 comprises a wireless VPN router[not shown] to facilitate data exchange between the LAN 250 and mobiledevice 100. The concept of a wireless VPN router is new in the wirelessindustry and implies that a VPN connection can be established directlythrough a specific wireless network to mobile device 100. Thepossibility of using a wireless VPN router has only recently beenavailable and could be used when the new Internet Protocol (IP) Version6 (IPV6) arrives into IP-based wireless networks. This new protocol willprovide enough IP addresses to dedicate an IP address to every mobiledevice, making it possible to push information to a mobile device at anytime. An advantage of using a wireless VPN router is that it could be anoff-the-shelf VPN component, not requiring a separate wireless gatewayand separate wireless infrastructure to be used. A VPN connection wouldpreferably be a Transmission Control Protocol (TCP)/IP or User DatagramProtocol (UDP)/IP connection to deliver the messages directly to mobiledevice 100 in this variant implementation.

Messages intended for a user of mobile device 100 are initially receivedby a message server 268 of LAN 250. Such messages may originate from anyof a number of sources. For instance, a message may have been sent by asender from a computer 262 b within LAN 250, from a different mobiledevice [not shown] connected to wireless network 200 or to a differentwireless network, or from a different computing device or other devicecapable of sending messages, via the shared network infrastructure 224,and possibly through an application service provider (ASP) or Internetservice provider (ISP), for example.

Message server 268 typically acts as the primary interface for theexchange of messages, particularly e-mail messages, within theorganization and over the shared network infrastructure 224. Each userin the organization that has been set up to send and receive messages istypically associated with a user account managed by message server 268.One example of a message server 268 is a Microsoft Exchange™ Server. Insome implementations, LAN 250 may comprise multiple message servers 268.Message server 268 may also be adapted to provide additional functionsbeyond message management, including the management of data associatedwith calendars and task lists, for example.

When messages are received by message server 268, they are typicallystored in a message store [not explicitly shown], from which messagescan be subsequently retrieved and delivered to users. For instance, ane-mail client application operating on a user's computer 262 a mayrequest the e-mail messages associated with that user's account storedon message server 268. These messages would then typically be retrievedfrom message server 268 and stored locally on computer 262 a.

When operating mobile device 100, the user may wish to have e-mailmessages retrieved for delivery to the handheld. An e-mail clientapplication operating on mobile device 100 may also request messagesassociated with the user's account from message server 268. The e-mailclient may be configured (either by the user or by an administrator,possibly in accordance with an organization's information technology(IT) policy) to make this request at the direction of the user, at somepre-defined time interval, or upon the occurrence of some pre-definedevent. In some implementations, mobile device 100 is assigned its owne-mail address, and messages addressed specifically to mobile device 100are automatically redirected to mobile device 100 as they are receivedby message server 268.

To facilitate the wireless communication of messages and message-relateddata between mobile device 100 and components of LAN 250, a number ofwireless communications support components 270 may be provided. In thisexample implementation, wireless communications support components 270comprise a message management server 272, for example. Messagemanagement server 272 is used to specifically provide support for themanagement of messages, such as e-mail messages, that are to be handledby mobile devices. Generally, while messages are still stored on messageserver 268, message management server 272 can be used to control when,if, and how messages should be sent to mobile device 100. Messagemanagement server 272 also facilitates the handling of messages composedon mobile device 100, which are sent to message server 268 forsubsequent delivery.

For example, message management server 272 may: monitor the user's“mailbox” (e.g. the message store associated with the user's account onmessage server 268) for new e-mail messages; apply user-definablefilters to new messages to determine if and how the messages will berelayed to the user's mobile device 100; compress and encrypt newmessages (e.g. using an encryption technique such as Data EncryptionStandard (DES) or Triple DES) and push them to mobile device 100 via theshared network infrastructure 224 and wireless network 200; and receivemessages composed on mobile device 100 (e.g. encrypted using TripleDES), decrypt and decompress the composed messages, re-format thecomposed messages if desired so that they will appear to have originatedfrom the user's computer 262 a, and re-route the composed messages tomessage server 268 for delivery.

Certain properties or restrictions associated with messages that are tobe sent from and/or received by mobile device 100 can be defined (e.g.by an administrator in accordance with IT policy) and enforced bymessage management server 272. These may include whether mobile device100 may receive encrypted and/or signed messages, minimum encryption keysizes, whether outgoing messages must be encrypted and/or signed, andwhether copies of all secure messages sent from mobile device 100 are tobe sent to a pre-defined copy address, for example.

Message management server 272 may also be adapted to provide othercontrol functions, such as only pushing certain message information orpre-defined portions (e.g. “blocks”) of a message stored on messageserver 268 to mobile device 100. For example, when a message isinitially retrieved by mobile device 100 from message server 268,message management server 272 is adapted to push only the first part ofa message to mobile device 100, with the part being of a pre-definedsize (e.g. 2 KB). The user can then request more of the message, to bedelivered in similar-sized blocks by message management server 272 tomobile device 100, possibly up to a maximum pre-defined message size.

Accordingly, message management server 272 facilitates better controlover the type of data and the amount of data that is communicated tomobile device 100, and can help to minimize potential waste of bandwidthor other resources.

It will be understood by persons skilled in the art that messagemanagement server 272 need not be implemented on a separate physicalserver in LAN 250 or other network. For example, some or all of thefunctions associated with message management server 272 may beintegrated with message server 268, or some other server in LAN 250.Furthermore, LAN 250 may comprise multiple message management servers272, particularly in variant implementations where a large number ofmobile devices need to be supported.

In some embodiments described herein, certificates are used in theprocessing of encoded messages, such as e-mail messages, that areencrypted and/or signed. While Simple Mail Transfer Protocol (SMTP),RFC822 headers, and Multipurpose Internet Mail Extensions (MIME) bodyparts may be used to define the format of a typical e-mail message notrequiring encoding, Secure/MIME (S/MIME), a version of the MIMEprotocol, may be used in the communication of encoded messages (i.e. insecure messaging applications). S/MIME enables end-to-end authenticationand confidentiality, and provides data integrity and privacy from thetime an originator of a message sends a message until it is decoded andread by the message recipient. In other embodiments described herein,other standards and protocols may be employed to facilitate securemessage communication, such as Pretty Good Privacy™ (PGP) and variantsof PGP such as OpenPGP, for example. It will be understood that wherereference is generally made to “PGP” herein, the term is intended toencompass any of a number of variant implementations based on the moregeneral PGP scheme.

Secure messaging protocols such as S/MIME and PGP-based protocols relyon public and private encryption keys to provide confidentiality andintegrity. Data encoded using a private key of a private key/public keypair can only be decoded using the corresponding public key of the pair,and data encoded using a public key of a private key/public key pair canonly be decoded using the corresponding private key of the pair. It isintended that private key information never be made public, whereaspublic key information is shared.

For example, if a sender wishes to send a message to a recipient inencrypted form, the recipient's public key is used to encrypt a message,which can then be decrypted only using the recipient's private key.Alternatively, in some encoding techniques, a one-time session key isgenerated and used to encrypt the body of a message, typically with asymmetric encryption technique (e.g. Triple DES). The session key isthen encrypted using the recipient's public key (e.g. with a public keyencryption algorithm such as RSA), which can then be decrypted onlyusing the recipient's private key. The decrypted session key can then beused to decrypt the message body. The message header may be used tospecify the particular encryption scheme that must be used to decryptthe message. Other encryption techniques based on public keycryptography may be used in variant implementations. However, in each ofthese cases, only the recipient's private key may be used to facilitatesuccessful decryption of the message, and in this way, theconfidentiality of messages can be maintained.

As a further example, a sender may sign a message using a digitalsignature. A digital signature is a digest of the message (e.g. a hashof the message) encoded using the sender's private key, which can thenbe appended to the outgoing message. To verify the digital signature ofthe message when received, the recipient uses the same technique as thesender (e.g. using the same standard hash algorithm) to obtain a digestof the received message. The recipient also uses the sender's public keyto decode the digital signature, in order to obtain what should be amatching digest for the received message. If the digests of the receivedmessage do not match, this suggests that either the message content waschanged during transport and/or the message did not originate from thesender whose public key was used for verification. Digital signaturealgorithms are designed in such a way that only someone with knowledgeof the sender's private key should be able to encode a signature thatthe recipient will decode correctly using the sender's public key.Therefore, by verifying a digital signature in this way, authenticationof the sender and message integrity can be maintained.

An encoded message may be encrypted, signed, or both encrypted andsigned. In S/MIME, the authenticity of public keys used in theseoperations is validated using certificates. A certificate is a digitaldocument issued by a certificate authority (CA). Certificates are usedto authenticate the association between users and their public keys, andessentially, provides a level of trust in the authenticity of the users'public keys. Certificates contain information about the certificateholder, with certificate contents typically formatted in accordance withan accepted standard (e.g. X.509). The certificates are typicallydigitally signed by the certificate authority.

In PGP-based systems, a PGP key is used, which is like an S/MIMEcertificate in that it contains public information including a publickey and information on the key holder or owner. Unlike S/MIMEcertificates, however, PGP keys are not generally issued by acertificate authority, and the level of trust in the authenticity of aPGP key typically requires verifying that a trusted individual hasvouched for the authenticity of a given PGP key.

For the purposes of the specification and in the claims, the term“certificate” is used generally to describe a construct used to providepublic keys for encoding and decoding messages and possibly informationon the key holder, and may be deemed to include what is generally knownas a “PGP key” and other similar constructs.

Standard e-mail security protocols typically facilitate secure messagetransmission between non-mobile computing devices (e.g. computers 262 a,262 b of FIG. 4; remote desktop devices). In order that signed messagesreceived from senders may be read from mobile device 100 and thatencrypted messages be sent from mobile device 100, mobile device 100 isadapted to store public keys (e.g. in S/MIME certificates, PGP keys) ofother individuals. Keys stored on a user's computer 262 a will typicallybe downloaded from computer 262 a to mobile device 100 through cradle264, for example.

Mobile device 100 may also be adapted to store the private key of thepublic key/private key pair associated with the user, so that the userof mobile device 100 can sign outgoing messages composed on mobiledevice 100, and decrypt messages sent to the user encrypted with theuser's public key. The private key may be downloaded to mobile device100 from the user's computer 262 a through cradle 264, for example. Theprivate key is preferably exchanged between the computer 262 a andmobile device 100 so that the user may share one identity and one methodfor accessing messages.

User computers 262 a, 262 b can obtain S/MIME certificates and PGP keysfrom a number of sources, for storage on computers 262 a, 262 b and/ormobile devices (e.g. mobile device 100). These certificate sources maybe private (e.g. dedicated for use within an organization) or public,may reside locally or remotely, and may be accessible from within anorganization's private network or through the Internet, for example. Inthe example shown in FIG. 4, multiple public key infrastructure (PKI)servers 280 associated with the organization reside on LAN 250. PKIservers 280 include a CA server 282 that may be used for issuing S/MIMEcertificates, a Lightweight Directory Access Protocol (LDAP) server 284that may be used to search for and download S/MIME certificates and/orPGP keys (e.g. for individuals within the organization), and an OnlineCertificate Status Protocol (OCSP) server 286 that may be used to verifythe revocation status of S/MIME certificates, for example.

Certificates and/or PGP keys may be retrieved from LDAP server 284 by auser computer 262 a, for example, to be downloaded to mobile device 100via cradle 264. However, in a variant implementation, LDAP server 284may be accessed directly (i.e. “over the air” in this context) by mobiledevice 100, and mobile device 100 may search for and retrieve individualcertificates and PGP keys through a mobile data server 288. Similarly,mobile data server 288 may be adapted to allow mobile device 100 todirectly query OCSP server 286 to verify the revocation status of S/MIMEcertificates.

In variant implementations, only selected PKI servers 280 may be madeaccessible to mobile devices (e.g. allowing certificates to bedownloaded only from a user's computer 262 a, 262 b, while allowing therevocation status of certificates to be checked from mobile device 100).

In variant implementations, certain PKI servers 280 may be madeaccessible only to mobile devices registered to particular users, asspecified by an IT administrator, possibly in accordance with an ITpolicy, for example.

Other sources of S/MIME certificates and PGP keys [not shown] mayinclude a Windows certificate or key store, another secure certificateor key store on or outside LAN 250, and smart cards, for example.

In at least one embodiment, a policy engine 290 resides in LAN 250. Insome embodiments of the systems and methods described herein, the policyengine 290 is provided by way of a PGP Universal Server developed by PGPCorporation. This is only one example. In variant embodiments, thepolicy engine may be implemented in some other device or construct otherthan a PGP Universal Server, and may be applied in the context ofprotocols other than PGP (e.g. in an S/MIME policy engine). For example,an Entrust Entelligence Messaging Server (EMS) may be employed.

In this example, a PGP Universal Server 290 is adapted to communicatewith a user's desktop computer (e.g. 262 a) and the user's mobile device(e.g. 100 via message management server 272), and may be further adaptedto encrypt messages and enforce compliance of security requirements withrespect to messages being sent by the user, based on policiesestablished by an administrator, for example. The placement of PGPUniversal Server 290 in LAN 250 as shown in FIG. 4 is provided by way ofexample only, and other placements and configurations are possible.Depending on the placement of the PGP Universal Server 290 and theparticular configuration of LAN 250 in which PGP Universal Server 290may be employed, the level of control over processed messages that aresubject to security encoding, and in particular, over messages beingsent by a user may vary.

For example, PGP Universal Server 290 may be adapted to directly processall outgoing messages (i.e. messages being sent by the user from theuser's desktop computer, mobile device, or other computing device to oneor more intended recipients), where it will make decisions on whichmessages to encrypt and/or sign, if at all, in accordance with policiesdefined on the PGP Universal Server 290 as configured by theadministrator. If a policy dictates that a message about to be sent bythe user to a particular domain or pertaining to a particular subject isto be encrypted and signed using PGP for example, the PGP UniversalServer 290 may itself encrypt and sign the message before transmission.

Alternatively, the user, through a PGP-enabled messaging application onthe user's computing device that communicates with PGP Universal Server290 for example, may download security policy data from the PGPUniversal Server 290 to the user's computing device. The user or theapplication may then be directed to encrypt and sign the message beforetransmission, based on the security policy data obtained.

Accordingly, PGP Universal Server 290 provides the ability to enforcecentralized policy based on domains and other mechanisms.

The PGP Universal Server 290 may also be adapted to store, validate, andotherwise manage PGP keys, and to retrieve PGP keys from remote keystores when the keys are required to encode (e.g. encrypt and/or sign)messages. Where requested by a user or application, PGP Universal Server290 may also provide stored or retrieved PGP keys to the user as needed.

By adopting the use of a policy engine such as that implemented by a PGPUniversal Server 290 as described herein by way of example, much of theburden associated with processing secure messages (e.g. e-mail), and inparticular, with deciding what messages are to be sent securely and whatsecurity encoding should apply on a case-by-case basis, can betransferred to the policy engine.

As noted previously in this description, embodiments described hereinrelate generally to systems and methods in which the performance ofcertain tasks is initiated while a user is composing a message andbefore a direction is received from the user to send the message. Thismay involve “pre-fetching” data that will likely be required in order tosend a message that is in the process of being composed by the user.

For example, the security policy defined by a policy engine (e.g. suchas that implemented in a PGP Universal Server 290 or an EMS not shown inFIG. 4) may be obtained by retrieving security policy data to thecomputing device while the user on the computing device is composing amessage. In particular, as soon as a user begins to compose a newmessage, security policy data provided by the policy engine may beupdated in a background process, for example.

As a further example, once a specific recipient is identified by theuser during composition of a message (e.g. by identifying the recipientin one of the “To:”, “Cc:”, or “Bcc:” fields of the user interfaceprovided by a messaging application), the potential recipient'scertificate (which may be a PGP key in some implementations) and thestatus of the certificate (e.g. from data retrieved from an OCSP server286 for an S/MIME certificate) may be retrieved in a background process.In some cases, the certificate data and/or certificate status data maybe retrievable from a certificate store on the computing device (e.g. amobile device). In some other cases, the certificate data and/orcertificate status may need to be retrieved from a server remote fromthe computing device.

Initiating the performance of such tasks in advance will generallyincrease the likelihood that a message will appear to be sent quicklyfrom the user's perspective, as the tasks required to complete the sendprocess might already have been completed, or at the very least, willhave already been initiated by the time the direction to send themessage is received from the user. By integrating this methodology intoa messaging application, such as an e-mail messaging application forexample, a more seamless user experience may be provided, particularlywhere the computing device is a mobile device.

At least some of the steps of the embodiments of a method describedherein are performed by an application executing and residing on thecomputing device. The application may be an e-mail or other messagingapplication, another application coupled to or otherwise integrated withthe e-mail or other messaging application (e.g. an add-on componentproviding the requisite functionality), or some other applicationprogrammed to perform such steps.

The computing device may be a desktop computer (which may, for instance,include a laptop computer or some other computing device that a mobiledevice may synchronize with), a mobile device, or some other computingdevice. The computing device may be coupled to a policy engine (e.g. asimplemented in a PGP Universal Server 290 of FIG. 4).

Reference is made in the embodiments described below to messages beingcomposed by a user of a computing device. In general, to initiate theprocess of composing a message, the user is typically first required toselect an appropriate icon or menu item provided by a messagingapplication (e.g. “Compose new message”). If the user wishes to composea message based on a previously received message (e.g. “Forward message”or “Reply to message”), the user may first need to select the previouslyreceived message before selecting the appropriate icon or menu item.

Once the user has finished composing the message, the user may thendirect the application to “send” the message (e.g. by selecting a “Sendmessage” button or menu item). In particular, if the message is to betransmitted securely to a recipient, the application will then usuallyperform further processing of the message (e.g. check the applicablesecurity policy, encrypt the message, etc.) before it is actually sentto the recipient of the message as identified by the user, as describedwith respect to one embodiment of the method below.

Referring first to FIG. 5A, a flowchart illustrating steps in a methodof processing messages being composed by a user of a computing device inone example embodiment is shown generally as 300.

At step 310, a request to compose a message is received from the user.

At step 320, the occurrence of at least one pre-defined triggering eventassociated with a message being composed by a user on the computingdevice is detected.

At step 330, for each triggering event that has been detected to haveoccurred at step 320, the performance of at least one pre-defined taskassociated with the respective triggering event is initiated while themessage is being composed by the user, after detecting the occurrence ofthe respective triggering event. Preferably, the task(s) associated withthe respective triggering event is/are initiated immediately after theoccurrence of the event is detected. Accordingly, the task(s) can beinitiated while the user is composing the message and before the messageis actually directed by the user to be sent.

Each task to be initiated at step 330 will have at least one specifictriggering event associated with it. As noted above, multiple tasks maybe associated with the same triggering event.

Subsequently, at step 340, a direction from the user to send the messagebeing composed on the computing device is received. The user may providesuch direction by pressing a “Send message” button provided by the userinterface of the application, or by selecting a corresponding “Sendmessage” menu item, for example.

Alternatively, the user may opt not to send the message by directing theapplication to cancel or discard the message [steps not shown]. In thatcase, the remaining steps of method 300 will not be performed.

At step 350, the message to be sent as directed by the user at step 340is further processed to prepare the message for transmission, whererequired. For example, the message may be re-formatted for transmission,or checked for compliance with an IT Policy governing the user of thecomputing device.

At step 360, the message will typically be sent to the messagerecipient(s) as identified by the user. However, as a result of thefurther processing performed at step 350, an error or some othercondition may be detected, and the application may be adapted towithhold or cancel the sending of the message at step 360.

In another embodiment, the message to be sent by the user is to betransmitted securely to its intended recipients. Accordingly, in thisother embodiment, at least some of the tasks that would be initiated atstep 330 of method 300 will specifically involve retrievingsecurity-related data, which would be required to further process themessage being composed by the user should the user direct the message tobe sent. There may be a number of different types of security-relateddata that could be required, and a different triggering event will beassociated with each. This variation of method 300 is described by wayof example with reference to FIG. 5B.

Referring to FIG. 5B, a flowchart illustrating steps in a method ofprocessing messages being composed by a user of a computing device inone example embodiment is shown generally as 300 b.

As in method 300, at step 310 of method 300 b, a request to compose amessage is first received from the user.

The application then monitors the user's composition of the message forvarious triggering events, as shown at steps 320 a and 320 b, forexample. It will be understood that other triggering events with whichother tasks are associated may be monitored in variant embodiments.

For instance, at step 320 a, the application detects when the user hasbegun composing the message. The user may be considered to have beguncomposing the message when, for example, the appropriate icon or menuitem is selected (e.g. “Compose new message”, “Forward message”, “Replyto message”), when a window for entering text in the message to becomposed appears, when text is actually entered in the window or when adocument is attached to the message by the user, or upon some otheraction as may be defined for a particular implementation.

At step 330 a, a determination of whether updated security policy dataneeds to be retrieved from a policy engine (e.g. as implemented in a PGPUniversal Server, EMS, or some other policy engine or server whichdictates and/or enforces specific encodings for messages being sent by auser) is initiated. This may require checking any security policy datathat is already stored on the computing device (e.g. the mobile device)and determining whether that data is stale and requires updating. Thelength of time that such data may exist on the computing device beforebecoming stale may be determined by an IT Policy or other securitypolicy or device configuration, for example.

The determination made at step 330 a is initiated upon detecting thatthe user has begun composing the message at step 320 a, which would bethe triggering event associated with the specific task of determiningwhether updated security policy data needs to be retrieved. However, adifferent triggering event may be associated with this specific task invariant embodiments.

Subsequently, at step 332 a, the retrieval of security policy data fromthe policy engine is initiated if it is determined at step 330 a thatupdated security policy data needs to be retrieved from the policyengine.

The flow of method steps continues at step 340. It will be understoodthat the tasks initiated at steps 330 a and/or 332 a may or may not becompleted by the time a user direction to send the message is receivedat step 340.

In a variant embodiment, step 330 a may not be performed, and securitypolicy data may be retrieved from the policy engine at step 332 aautomatically upon detecting that the user has begun composing themessage at step 320 a (or upon the occurrence of some other associatedtriggering event). This may be desirable if the most recent securitypolicy data is to be retrieved every time a new message is beingcomposed, regardless of when security policy data was last retrieved tothe computing device, for example.

Although there is a risk that the message being composed may ultimatelynot be sent, and therefore, the security policy data on the computingdevice may have been updated or retrieved unnecessarily, a trade-off ismade when steps 330 a and/or 332 a are performed. If the messagecomposed is actually sent, then some, if not all of the time required toupdate or retrieve the security policy data (which might otherwise bespent only after the user directs the message to be sent) can be spentin advance, thereby making the send process appear to be more seamlessfrom the user's perspective.

Meanwhile, at step 320 b, the application detects when the user hasidentified a recipient to which the message being composed is intendedto be sent. The user may be considered to have identified a messagerecipient by, for example, identifying the recipient in one of the“To:”, “Cc:”, or “Bcc:” fields of the user interface provided by amessaging application, or upon some other action as may be defined for aparticular implementation.

At step 330 b, retrieval of certificate data from a certificate store isinitiated upon detecting that the user has identified a messagerecipient while composing the message at step 320 b, which is thetriggering event associated with the specific task of retrievingcertificate data for the particular message recipient. However, othertriggering events may be associated with this specific task in variantembodiments.

The certificate data may be an S/MIME certificate, or a PGP key, forexample. The certificate store may reside on the computing device, or itmay reside on a server remote from the computing device (e.g. LDAPserver 284 of FIG. 4) from which the certificate data must be requested.

The retrieval of certificate data initiated at step 330 b will typicallybe associated with a certificate issued to an individual or entity, andin particular, the message recipient identified by the user. If themessage recipient is an alias for multiple individual recipients (e.g.identified by a mailing list or distribution list address), retrieval ofa certificate for each of the individual recipients may be initiated atstep 330 b.

It will be understood that that the retrieval of certificate datainitiated at step 330 b for a particular individual may not always besuccessful, as not all individuals may have been issued a certificate,for example.

Although there is a risk that the message being composed may ultimatelynot be sent, and therefore, certificates for potential messagerecipients may have been retrieved unnecessarily, a trade-off is madewhen step 330 b is performed. If the message composed is actually sent,then some, if not all of the time required to retrieve the requisitecertificate(s) (which might otherwise be spent only after the userdirects the message to be sent) can be spent in advance, thereby makingthe send process appear to be more seamless from the user's perspective.

Steps 332 b to 336 b as described below may be performed where thecertificate data being retrieved as a result of step 330 b beingperformed s provided in a certificate for which certificate status canbe verified.

At step 332 b, the application detects when the certificate data for theidentified message recipient has been retrieved to the computing deviceas initiated at step 330 b.

At step 334 b, a determination of whether updated certificate statusdata needs to be retrieved (e.g. from OCSP server 286 of FIG. 4) for theretrieved certificate is initiated. This may require checking a recordof when a certificate retrieved as a result of step 330 b beingperformed was last verified for revocation status, for example. Thelength of time that status data may exist on the computing device beforebecoming stale may be determined by an IT Policy or other securitypolicy or device configuration, for example.

Subsequently, at step 336 b, retrieval of certificate status data (e.g.revocation status) for one or more certificates is initiated if it isdetermined at step 334 b that updated certificate status data needs tobe retrieved.

The flow of method steps continues at step 340. It will be understoodthat the tasks initiated at steps 330 b, 334 b and/or 336 b may or maynot be completed by the time a user direction to send the message isreceived at step 340.

In a variant embodiment, step 334 b may not be performed, and retrievalof certificate status data may be initiated at step 336 b automaticallyupon detecting that the certificate for a message recipient has beenretrieved as a result of step 330 b being performed, or after detectingthat some other triggering event has occurred. This may be desirable ifthe most recent certificate status data is to be retrieved every time acertificate is retrieved for use, regardless of when the revocationstatus for the certificate was last verified, for example.

Although there is a risk that the message being composed may ultimatelynot be sent, and therefore, the certificate status data for one or morecertificates may have been updated or retrieved unnecessarily, atrade-off is made when steps 334 b and/or 336 b are performed. If themessage composed is actually sent, then some, if not all of the timerequired to update or retrieve the certificate status data (which mightotherwise be spent only after the user directs the message to be sent)can be spent in advance, thereby making the send process appear to bemore seamless from the user's perspective.

Certificate status data for which retrieval is initiated at step 336 bmay include certificate-related data other than that used to verifyrevocation status. For example, retrieval of data used to verify thetrust status, the validity (e.g. expiry), or key strength of acertificate retrieved as a result of step 330 b being performed may alsobe initiated at this step.

In this example embodiment, the data that is “pre-fetched” while amessage is being composed by the user includes security policy data,certificate data, and certificate status data. Retrieval of a subset ofthis data, additional data and/or different data may be initiated invariant embodiments, and the retrieval of particular data may beassociated with one or more different triggering events.

It will be understood that additional instances of steps 320 b and 330b, as well as instances of steps 332 b to 336 b at which the status ofcertificates can be verified, may be repeated and executed concurrentlyin order to initiate the retrieval of certificate data and optionallycertificate status data for multiple message recipients, where multiplemessage recipients are identified for the same message by the user.Similarly, instances of steps 320 b to 336 b and steps 320 a to 332 amay be executed concurrently in parallel background processes. Othertriggering events may be monitored, and their associated tasks may alsobe initiated concurrently in parallel background processes.

At step 340, a direction from the user to send the message beingcomposed on the computing device is received. The user may provide suchdirection by pressing a “Send message” button provided on the userinterface of the application, or by selecting a corresponding “Sendmessage” menu item, for example. Alternatively, the user may opt not tosend the message by directing the application to cancel or discard themessage [steps not shown]. In that case, the remaining steps of method300 b will not be performed.

At step 350, the message to be sent as directed by the user at step 340is further processed to prepare the message for transmission, whererequired. For example, the message may be re-formatted for transmission,or checked for compliance with an IT Policy.

At this step, the message may be further processed using the data thathas been retrieved at previous steps of method 300 b. For example, thesecurity policy data retrieved as a result of step 332 a being performedmay be used to determine the specific security encoding that is to beapplied to the message before transmission. The certificate dataretrieved as a result of step 330 b being performed may be used toencode the message for transmission, and the certificate status dataretrieved as a result of step 336 b being performed may be used toverify the status of the certificate before it is permitted for use inencoding the message for transmission.

Additional input from the user may also be required in the furtherprocessing of the message at step 350. For example, if there is aproblem with the status of a certificate or if a certificate for aparticular recipient is not found, the user may be prompted to confirmwhether the message should still be sent. If multiple certificates thatare potentially associated with an identified recipient have beenretrieved, the user may be required to select the appropriatecertificate. If the user has selected a particular encoding for themessage but the selected encoding does not comply with security policydata retrieved, the user may be prompted to confirm whether the messageshould still be sent.

These are examples only, and other tasks may be performed in the furtherprocessing of the message at step 350 in variant embodiments.

At step 360, the message will typically be sent to the messagerecipient(s) as identified by the user. However, as a result of thefurther processing performed at step 350, an error or some othercondition may be detected, and the application may be adapted towithhold or cancel the sending of the message at step 360.

The steps of the methods described herein may be provided as executablesoftware instructions stored on computer-readable media, which mayinclude transmission-type media.

The invention has been described with regard to a number of embodiments.However, it will be understood by persons skilled in the art that othervariants and modifications may be made without departing from the scopeof the invention as defined in the claims appended hereto.

1. A mobile device comprising a microprocessor, wherein themicroprocessor is configured to: identify a triggering event that hasoccurred during composition of a message; request certificate data froma certificate store in response to the triggering event, wherein thecertificate data corresponds to a message recipient of the message;detect when the certificate data has been retrieved to the mobiledevice; and retrieve certificate status data, wherein the certificatestatus data is used to verify the status of a certificate upon detectingthat the certificate data has been retrieved to the mobile device;wherein the microprocessor is configured to initiate requesting thecertificate data, detecting when the certificate data has been retrievedto the mobile device and retrieving the certificate status data before auser direction to send the message is received.
 2. The device of claim1, wherein the microprocessor is further configured to process themessage using requested certificate data.
 3. The device of claim 1,wherein the microprocessor is further configured to receive the userdirection to send the message, and to send the message to the messagerecipient.
 4. The device of claim 1, wherein the certificate datarequested from the certificate store comprises a certificate associatedwith the message recipient.
 5. The device of claim 1, wherein thecertificate store resides on a server remote from the mobile device. 6.A mobile device comprising a microprocessor, wherein the microprocessoris configured to: identify a triggering event in which a user selectionof an icon or menu item is made to initiate composition of a message;request certificate data from a certificate store in response to thetriggering event, wherein the certificate data corresponds to a messagerecipient of the message; detect when the certificate data has beenretrieved to the mobile device; and retrieve certificate status data,wherein the certificate status data is used to verify the status of acertificate upon detecting that the certificate data has been retrievedto the mobile device; wherein the microprocessor is configured toinitiate requesting the certificate data, detecting when the certificatedata has been retrieved to the mobile device and retrieving thecertificate status data before a user direction to send the message isreceived.
 7. The device of claim 6, wherein the microprocessor isfurther configured to process the message using requested certificatedata.
 8. The device of claim 6, wherein the microprocessor is furtherconfigured to receive the user direction to send the message, and tosend the message to the message recipient.
 9. The device of claim 6,wherein the certificate data requested from the certificate storecomprises a certificate associated with the message recipient.
 10. Thedevice of claim 6, wherein the certificate store resides on a serverremote from the mobile device.
 11. A mobile device comprising amicroprocessor, wherein the microprocessor is configured to: identify atriggering event in which a window for entering text in a message to becomposed appears in a screen of the mobile device or when the text isfirst entered in the window; request certificate data from a certificatestore in response to the triggering event, wherein the certificate datacorresponds to a message recipient of the message; detect when thecertificate data has been retrieved to the mobile device; and retrievecertificate status data, wherein the certificate status data is used toverify the status of a certificate upon detecting that the certificatedata has been retrieved to the mobile device; wherein the microprocessoris configured to initiate requesting the certificate data, detectingwhen the certificate data has been retrieved to the mobile device andretrieving the certificate status data before a user direction to sendthe message is received.
 12. The device of claim 11, wherein themicroprocessor is further configured to process the message usingrequested certificate data.
 13. The device of claim 11, wherein themicroprocessor is further configured to receive the user direction tosend the message, and to send the message to the message recipient. 14.The device of claim 11, wherein the certificate data requested from thecertificate store comprises a certificate associated with the messagerecipient.
 15. The device of claim 11, wherein the certificate storeresides on a server remote from the mobile device.
 16. A mobile devicecomprising a microprocessor, wherein the microprocessor is configuredto: identify a triggering event in which a document is attached to amessage during composition of the message; request certificate data froma certificate store in response to the triggering event, wherein thecertificate data corresponds to a message recipient of the message;detect when the certificate data has been retrieved to the mobiledevice; and retrieve certificate status data, wherein the certificatestatus data is used to verify the status of a certificate upon detectingthat the certificate data has been retrieved to the mobile device;wherein the microprocessor is configured to initiate requesting thecertificate data, detecting when the certificate data has been retrievedto the mobile device and retrieving the certificate status data before auser direction to send the message is received.
 17. The device of claim16, wherein the microprocessor is further configured to process themessage using requested certificate data.
 18. The device of claim 16,wherein the microprocessor is further configured to receive the userdirection to send the message, and to send the message to the messagerecipient.
 19. The device of claim 16, wherein the certificate datarequested from the certificate store comprises a certificate associatedwith the message recipient.
 20. The device of claim 16, wherein thecertificate store resides on a server remote from the mobile device.